Chemical & Physical Changes

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances with different properties.

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

Give an example of a chemical change.

Back

Cooking an egg is an example of a chemical change because it transforms the raw egg into a new substance.

Front

Give an example of a physical change.

Back

Melting wax is an example of a physical change because it changes from solid to liquid but remains wax.

Front

What happens when salt dissolves in water?

Back

When salt dissolves in water, it undergoes a physical change because the salt can be recovered by evaporating the water.

Front

What is a precipitate?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What is a phase change?

Back

A phase change is a physical change that occurs when a substance changes from one state of matter to another, such as solid to liquid.

Front

What is an example of a chemical change involving gas?

Back

When vinegar and baking soda are mixed, they produce carbon dioxide gas, which is a chemical change.

Front

What is the difference between a chemical change and a physical change?

Back

A chemical change results in the formation of new substances, while a physical change does not change the chemical identity of the substance.

Front

What is an example of a physical change that can be reversed?

Back

Freezing water to make ice is a physical change that can be reversed by melting the ice back into water.